#include <iostream>
using namespace std;

const int N = 1010;

int n;
int a[N];
int f[N];
int res = 0;

int main()
{
    cin >> n;
    for (int i = 1; i <= n; ++i)
        cin >> a[i];
    for (int i = 1; i <= n; ++i)
    {
        f[i] = a[i];
        for (int j = 1; j < i; ++j)
            if (a[i] > a[j])
                f[i] = max(f[i], f[j] + a[i]);
    }
    for (int i = 1; i <= n; ++i)
        res = max(res, f[i]);
    cout << res;
}